I found this spool data from my old setup. Stock '99 motor with forged rods. BEGI cast manifold, GT2871 .64ar, 3" ARTech exhaust. Looks like it was spooling a good bit faster than yours on what sounds like a similar setup. I think the real garrett would help a lot.

 

Oh yeah....definitely spools better. Hopefully the 2860 would spool like that too. Thank you!